Polymers having carboxyl groups are known. These polymers can vary in nature from high molecular weight plastics and elastomers to low molecular weight liquids, and can have very low to very high weight percent carboxyl contents. The polymers are insolubilized by reacting them with crosslinking or cure agents to form vulcanized articles as films and coatings, caulks, or dimentionally stable molded products. Different types of materials are used as cross-linking or cure agents, the most common materials being metal salts or oxides (see U.S Pat. Nos. 2,604,668; 2,649,439; 2,669,550; 2,724,707; 2,726,230 and 3,404,134). The inventor has discovered a new and improved cure system for curing carboxyl-containing polymers.